At present, most conventional internal combustion engines generate kinetic energy by moving a piston reciprocally and using components such as link rods or crankshaft to achieve the effect, and there are two common types of internal combustion engines, respectively; a two-stroke internal combustion engine and a four-stroke internal combustion engine.
In the two-stroke internal combustion engine, a fuel gas is compressed when the piston ascends, and an ignition system is provided for igniting the compressed fuel gas to produce an explosion when the piston ascends to a top dead center. When the piston descends to apply a force to a cam, the crankshaft is linked to rotate and generate kinetic energy. In other words, when the piston is moved reciprocally once, the crankshaft is rotated for a round (360 degrees) to generate kinetic energy for one time. When the piston descends, a top end of the piston passes through an exhaust port first and then descends and passes through the intake port. Now, the compressed fuel gas in a crankshaft box enters into the cylinder, gets ready for the next cycle of combustion, and exhausts some of the waste gas produced after the combustion. When the piston descends to a bottom dead center, the crankshaft driven by the piston through the link rod drives the piston to ascend again by a reverse inertia force in the rotation, and the fuel gas entering from the intake port into the cylinder is pushed upwardly and compressed to produce another explosion and a cycle of generating kinetic energy.
In summation, the two-stroke internal combustion engine does not come with an intake valve, an exhaust valve or a related transmission device or component, so that the structure is relatively simpler, but its application still has the following drawbacks:
1. Since there is no driving device for exhaustion, therefore when the fuel gas passes through the intake port and enters into the cylinder, only a portion of the waste gas produced by the explosion and combustion of the fuel gas and stored in the crankshaft box is compressed and exhausted to the outside, but most of the waste gas still remains in the cylinder and mixes with the recently entered fuel gas. Therefore, the fuel gas cannot be combusted completely, and the exhausted gas fails to meet the requirements of environmental protection.
2. When the piston ascends to compress the fuel gas, a portion of the waste gas originally stored in the cylinder is compressed to the exhaust port and exhausted to the outside, but a portion of the compressed fresh fuel gas is also exhausted altogether, and thus causing a waste of fuel gas (or energy source).
3. The waste gas produced by the explosion and combustion of the fuel gas in the cylinder cannot be exhausted completely and a large quantity of waste gas still remains and mixes directly with the fresh fuel gas provided for the next combustion cycle. Therefore, when the fuel gas mixed with the waste gas is exploded and combusted, the quantity of kinetic energy is smaller and the expected using effect cannot be achieved.
4. When the piston ascends from the bottom dead center to the top dead center (or the crankshaft rotates 180 degrees), the compressed fuel gas is exploded and combusted, so that the piston will descend instantaneously to produce kinetic energy once (Now, the crankshaft has another rotation of 180 degrees). After the piston descends to the bottom dead center, the piston will ascend with the rotation of the crankshaft to compress the fuel gas again and prepare for the next production of kinetic energy, and the reciprocal two-stroke internal combustion engine can provide kinetic energy through such cycle continuously. However, this method of generating kinetic energy has the drawbacks of wasting energy source and incurring low efficiency. As to the operability of the crankshaft and the piston, the piston ascends to the top dead center after the fuel gas is exploded and combusted, and then the piston will descend immediately to apply a force to the crankshaft and drives the crankshaft to rotate, so as to generate the kinetic energy. After the crankshaft rotates 180 degrees to provide kinetic energy, the piston will rotate for 180 degrees from the bottom dead center in a reverse direction, so as to ascend and compress the fuel gas and the piston can no longer apply a force to the crankshaft. Although the crankshaft still continues its rotation of 180 degrees, the rotation mainly relies on the reverse inertia force produced by the previous rotation of 180 degrees but not the driving force continuously provided by the piston. The piston does not provide the driving force to the crankshaft in both the upward and downward strokes, and it just provides the driving force in the downward rotary direction only. Obviously, the kinetic energy generated by the rotation of the crankshaft can achieve at most half of the expected effect, and the efficiency is low. In addition, the piston at the top and bottom dead centers performs a 180-degree reciprocal motion instantaneously, not just adversely affecting the effect of the inertia force, but also causing a pulse pause that retards the motion speed when the piston is situated at the top and bottom dead centers. When the piston ascends to compress the fuel gas, the piston will be retarded by the resistance of the fuel gas to reduce the ascending speed and pressure. In practical application, the rotation of the crankshaft linked with the piston will be affected, and a large quantity of the generated kinetic energy will be consumed and wasted. Such conventional two-stroke internal combustion engine cannot provide high-efficiency kinetic energy.
On the other hand, the four-stroke internal combustion engine improves the issue of having a large quantity of waste gas remained in the cylinder after the exposition and combustion of the fuel gas in the two-stroke internal combustion engine. The four-stroke internal combustion engine also generates kinetic energy by the reciprocal motion of the piston linked to the crankshaft. The difference between the four-stroke and two-stroke internal combustion engines mainly resides on that the four-stroke internal combustion engine moves the piston reciprocally for two times, and the crankshaft rotates for two rounds (or 720 degrees) before generating the kinetic energy once. In other words, when the intake valve and exhaust valve are closed, the piston compresses the fuel gas in the cylinder during the first-time ascending stroke. When the piston ascends to the top dead center, the fuel gas is ignited by the ignition system to exploded, and then the first-time descending stroke will take place immediately and the crankshaft will be linked and rotated by the applied force to generate kinetic energy for one time. When the piston descends to the bottom dead center in the first-time descending stroke, the second-time ascending stroke takes place by the reverse inertia force of the crankshaft. Since the intake valve is still closed, and the exhaust valve is switched to an open status, therefore the waste gas remained from the previous explosion and combustion, and the ascending piston compresses and exhausts the waste gas from the exhaust valve to the outside. After the piston ascends to the top dead center for the second time, the second-time descending stroke take place automatically by the reverse inertia force of the crankshaft. In the meantime, the exhaust valve is switched to the closed status, and the intake valve is switched to the open status, so that the fresh fuel gas can enters directly from the intake valve into the cylinder, and when the piston descends to the bottom dead center, another cycle of ascending the piston to compress the fuel gas takes place again by the reverse inertia force.
Undeniably, the aforementioned four-stroke internal combustion engine is capable of exhausting the waste gas produced by the explosion and combustion of the fuel gas to the outside when the piston ascends to compress and exhaust waste gas. As a result, the quantity of the waste gas remained in the cylinder is less (since there is a gap between the cylinder and the cylinder cover, therefore the waste gas produced after the explosion and combustion cannot be exhausted completely, and a portion of the waste gas still remains), and the fuel gas can be combusted more completely, and the exhausted gas can meet the requirements of environmental protection. Since the piston rotates the crankshaft through a linear reciprocal motion to generate kinetic energy, therefore the piston requires a reverse 180-degree motion at the top dead center and the bottom dead center. Obviously, the inertia force has an adverse effect on the aforementioned piston, and the piston situated at the top and bottom dead centers will have a pulse pause, and when the piston ascends, the piston is affected by the resistance of the fuel gas, and the efficiency of generating kinetic energy by the crankshaft will be affected. Therefore, the conventional four-stroke internal combustion engine still cannot provide high-efficiency kinetic energy. Particularly, two strokes are added to the piston in order to successfully exhaust the waste gas produced by the combustion to the outside from the cylinder (In other words, the piston must carry out the reciprocal motion twice, and the crankshaft must be rotated for two rounds). Such internal combustion engine not just wastes the kinetic energy generated by two strokes only, but also fails to comply with the cost-effectiveness (according to the principle of mechanics).
Further, some manufacturers adopt a rotary engine such as the Wankel rotary engine) comprising three parts, respectively: a rotor seat with an elliptical space; a triangular rotor assembly accommodated in the elliptical space of the rotor seat and having a driving gear and a stationary gear engaged with one another; and an eccentric shaft assembly passed through and installed to the rotor assembly, such that the rotor assembly can perform an elliptical motion at the rotor seat. Since the triangular rotor assembly compresses the fuel gas along the curve of the elliptical space of the rotor seat, the rotary engine has the following drawbacks:
1. The complexity, precision, and manufacturing cost of the whole structure are high.
2. The triangular rotor assembly has a less airtight effect with the rotor during the rotation.
3. Since the rotation of the rotor assembly is driven by the rotation of the eccentric shaft assembly, but not integrally rotated according to the inertia motion, therefore the rotation of the rotor assembly is substantially in a parabolic shape of a centrifugal force and must be balance by pulling back the rotating force of the eccentric shaft assembly, and the compression stroke consumes kinetic energy to reduce the efficiency of generating kinetic energy.
4. Since the rotor assembly is a triangular assembly with three sides provided for performing different four-stroke cycles simultaneously, therefore the shape of the rotor assembly cannot be changed to triangular, the compression ratio cannot be improved easily, and the efficiency of generating kinetic energy is low.